Sunday, November 30, 2008

Water water everywhere and lots of drops to drink

As a biologist, I spend a lot of time studying life in a drop of water ... or sometimes I drop myself into water to study life. On rare occasions I depict life with paint, brush, and watercolor.

People often ask where we get our water at the field camp. We wash dishes, clothes, and (not often enough) our bodies using melted sea ice. When sea water freezes, most of the salt is "squeezed out" in the form of brine as water crystals form. As seen above, these brine channels form "crater star" patterns that are visible on the ice surface. Underwater, they form the ice stalactites that we ponder while doing a safety stop at the end of scuba dives.

Not all the brine drains from sea ice, however, and this brackish water is not suitable to drink. Instead, our potable water is brought in by helicopter from McMurdo Station. We use about 5 gallons a day when there are 7-8 people in camp, but lately we have been visited by many other scientists working in the area. As a result, our outhouse is getting a workout and our drinking water is gone.

Fortunately, there are many snow banks surrounding camp. Snow is, of course, essentially frozen rain. If you collect enough drops you can drink rainwater. Likewise, if you scoop up enough snow and melt it, you have "fresh" water to drink. We boil it first for proper hygiene: Skua Gulls fly overhead, and an occasional penguin waddles thru the snow.

To be honest, melted snow here doesn't taste very good. I hope it's because of all the sand mixed with the snow, and not because of the birds.

Thursday, November 27, 2008

A view of above

There are temperate places on Earth where, looking through the forest canopy toward the night sky, one would find in the shadows vines clinging to crenated bark, moss hanging limp from branches, and hints of the heavens piercing heavy, moist air. Tonight, however, an upward glance from our sleeping bags reveals green arches, Jamesway blankets flapping in the wind, and an upside-down wardrobe of layers. Moments ago we were onions of polypropylene leggings and undershirts, silk socks, wool socks, Thinsulate glove liners and Gore-Tex glove shells, wind pants, briefs (not boxers), knickers, hats, gaiters, goggles, a Big Red parka, and bunny boots. Unwashed and unkempt, the outerwear is sprayed with the ocean, their fringes crusted in white. The innerwear is likewise moist, although sweat - being more organic than seawater - thankfully fails to encrust. We inhale dry desert air laden with Taylor Valley dust, and exhale the taste of instant decaf mixed with cocoa. Geologists, biologists, artists, and divers - eight souls on board a tiny camp at the edge of the world.

The layers sway as the Jamesway tosses and turns in the wind. Overhead are the thrashing sounds of flags made by schoolchildren, mounted on bamboo poles now bent by the katabatic wind. Their thrumming warns of danger and spawns thoughts of home. Will cargo straps fail and launch barrels through the tent? Will loves fail and pierce our hearts? We share smiles as our insulation holds, our isolation fades, and our workday is closed by sleep.

We relish a nighttime of sunshine at Explorers Cove, Antarctica. 

Tuesday, November 25, 2008

Mucking a dive hole

Muck: v. to clean up; especially to clear of manure or filth ...
Merriam-Webster online search

Although there's a difference between ice crystals and manure, the process of slinging debris is the same: Scoop it up, and flick it aside. In these photos, Claire shows how it's done.

First, scoop out dislodged ice using a dip net.

Then drain water from the ice and give it a toss!

Alternatively, you can fling the ice into the air and pull away the dip net. Mucking gives your forearms and shoulders a good workout...

Sunday, November 23, 2008

Bay of Wails

How cold is -2C (28F) water? Ask Steve Clabuesch. He was tending the first dive at the Bay of Sails. While preparing to deploy the down line, he got a little too close to the edge of the hole, and "whoooops!" In the drink he went. "Yeeeouch!"
I was back at camp taking a nap, when a tap on my shoulder announced that a helo was returning one of the field members because they fell in the dive hole. That message sent a chill down my spine, too! Fortunately, Steve was fine and I took his place tending the dives.

(photos by Dr. Sally Walker)

Thursday, November 20, 2008

Dirty Ice

One goal of our project is to determine the impact of sedimentation on marine organisms along western McMurdo Sound. In a nutshell, large amounts of sediment are blown out of the Taylor Valley onto the sea ice at Explorers Cove; this sediment accumulates on the multi-year ice in the Cove, as seen in the aerial photo below. (Yes, that's what the ice at Explorers Cove looks like from 500 ft. up!)

This massive amount of sediment is ultimately deposited into the sea by various processes. Under certain conditions, we suspect that sediment is episodically dumped onto the seafloor, burying marine organisms in ways that may preserve them as fossils. The results of our studies should provide a better understanding of the fossil record in this region of Antarctica.

Wind-blown sediment accumulates around structures on the sea ice, particularly the various types of cracks that form. These cracks range in size from tiny thermal cracks (seen above) to more massive tide cracks. The sediment grains trapped by these cracks absorb sunlight and help melt the ice. Freeze/thaw cycles and solar radiation, compounded by the multi-year nature of the ice, lead to the beautiful, treacherous ice topologies that our shins, chins, and tailbones are now encountering.

Compare the smooth surface of first-year ice at our Bay-of-Sails camp site (above) to the ten-year-old ice at Explorers Cove.

Sunday, November 16, 2008

A bit unstuck

The Herbertson Glacier site is finally finished! The Hotsy melted a nice hole, and in the process the stuck drill bits dropped to the seafloor. Today we loaded our dive gear on the ATV and snowmobiles, and set out to collect specimens, map the undersea topology, catalog organisms living under the ice, deploy sediment traps and experimental arrays, and add a new layer to our art/science project. Oh, and to recover those pesky drill bits.

The "down line" that we lower into the dive hole is decorated with flags and flashers; these help the divers find the hole while underwater. The down line has a basket on its end for lowering equipment and raising samples. A small bottle of emergency air rounds out the string of things lowered with the divers. Also seen here is a small hand winch we could use to help haul a diver out of the hole.

While the divers are underwater, the tenders must be prepared to help in any way. We carry first aid kits, hot water, and an emergency supply of oxygen (inside the grey box that Claire is holding).  Not to mention radios with spare batteries to call for help, if needed.

"Prepare for the worst; expect the best" is our motto ...

Thursday, November 13, 2008

Wet ones

I've had the privilege of working with some awesome scientific divers over the years, and I'd like to introduce a few of them here. The first is Dr. Joan Bernhard. I met "Joanie" during my first season in Antarctica, and we've remained close friends ever since. She is, in a sense, the sister I never had. (I haven't had the courage to pull her pigtails, though!) We collaborate on various projects, and often bounce ideas back and forth that ultimately lead to new adventures. We also spend a lot of time arguing about how to write our science papers. In fact,  I owe Joan comments on a manuscript right now, so I better quickly introduce two other divers and get right back to work on it.

The other two are Dr. Karen Sterling (above, and below right) and Mr. Doug Coons (below, left). To be honest, I don't remember how we got to know each other. I think that Karen wrote to me out of the blue, and Doug was recommended by someone from a local dive shop. (Maybe they will post comments to this blog to tell their story.) Both are tough as nails and have an incredible work ethic. In addition to working as a commercial diver, Doug was a medic in the New York National Guard; he is now completing a nursing degree. Karen lives in Manhattan and mixes her knowledge of finance and biology in the investment industry.

People from all walks of life have brought their extraordinary skills to our research program. I'd be nowhere without them, and this is true of modern science: it takes a strong team of passionate people to make progress. The notion that a scientist is the oddball sitting in a corner peering into a microscope (or telescope or mass spectrometer, or some other gizmo) is only a tiny part of the big picture. 

Oh, by the way: My sister Joan is an oddball sitting in a corner peering into her laser confocal microscope at Woods Hole Oceanographic Institute! (huh HUH, Joanie!)

Monday, November 10, 2008

A bit stuck

I've been away from blogging for a few days, and here's the culprit: a stuck drill bit, as shown underfoot by Steve Clabuesch. Unexpected problems like this are expected to happen in Antarctica. 

Over the past few days, we have been trying to establish a dive hole near the Herbertson Glacier. Although still within the New Harbor area, this site is very different from Explorers Cove in terms of the amount of sediment deposited from the Taylor Dry Valley; this makes it an important comparative sampling station.

It's about an hour away by snowmobile, and we must travel across some fairly bumpy sea ice to get there. We blazed a trail, set up a small shore camp, and moved the "Hotsy" hole melter to the site. As with blasting a dive hole, the first step is to drill a 5-inch (12.7-centimeter) diameter pilot hole through the sea ice. The next step is to insert a "hot finger" (a cylinder of tightly-wound metal tubing) which is heated by a diesel-fueled burner; this device melts the ice and creates a dive hole within a day or two.

We only got to step one. About 15-feet (3 meters) down, the drill bit hit water and instantly froze solid. This never happens in Explorers Cove, but it has happened to us several times over the past few seasons working in the Ferrar Glacier fjord. I'm not sure why ... perhaps there is super-cooled glacier water just under the ice? One thing is for sure: it will take a bit more skill to make this hole. I'll let you know how it goes...

Tuesday, November 4, 2008

Three of a kind

Introducing the other two people who put G-093 together: Sally Walker (above, sporting her first dribble from the New Harbor coffee pot) and Molly Miller.  Sally is posting updates on her Antarctic experiences as "Postcards from the Poles" at the Windows to the Universe site.  Molly's website has links to her Antarctic experiences, too.

Sally studies modern ecosystems and their transformation into fossilized remains -- a science called taphonomy, which is crucial for interpreting past conditions on earth (and for predicting its future). Molly is a geologist/paleontologist who has studied fossils in Antarctica for many years. Together, we hope to arrive at a better understanding of the fossilization of Antarctic marine critters by comparing and contrasting different settings nearshore environments along western McMurdo sound.

Above, the three of us pose for a photo at Explorers Cove field camp.

Monday, November 3, 2008

Coring never boring

One of our many science objectives is to examine the diversity (in other words, the number of different types) of small organisms on the sea floor in Explorers Cove, and to monitor changes in diversity over time. One way to accomplish this goal is for scuba divers to take sediment cores and bring these small samples to the surface for analysis. It is important that the divers take the cores haphazardly so that sampling bias is reduced -- in other words, sampling should be as random as possible so that the results are statistically sound. You can see a video of a diver taking sediment cores here; please also see the "skittle core" activity for K-12 students, developed in conjunction with a highly dedicated group of teachers that we work with.

Once the core reaches the surface, a scientist will slice it into sections that are one centimeter in thickness. Each section is then sieved, and the organisms within each slice are poured into storage bottles, which are refrigerated to keep the critters inside healthy. Back in the lab shack, the organisms in each sample are identified and counted. Simple statistical methods allow us to estimate the total population of a given organism at each dive site (we call these sites "sampling stations"). 

Doing this year-after-year allows us to plot changes in population over time. Shown here is Claire selecting a "good" core for analysis. (The best cores have perfectly clear water above the sediment, which indicates that minimal disturbance was caused by the coring process.) She is then seen cutting the core into 1-cm slices using a thin piece of metal, and then placing each slice into a sieve (in this case, she uses a 1-mm mesh size), and anything smaller than 1-mm diameter is washed away. The "sieve residue" is then seen being transferred to a storage bottle. Coring is one of my favorite things to do in Antarctica...